Navigation instrument



11, 13. w c WADEMAN 2,165,$9

NAVIGATION INSTRUMENT Filed Jan. 27, 1936 Sheets-Sheet 1 [n z/entor;

Patented July 11, 1939 NAVIGATKON mew/Inn's Warrington C. Wademan, WestOrange, N. 5. Application January 21, 1936, Serial No. 60,961

1 Claim.

a mechanically operated radio sending and receiving set, an automaticrelay set and a device for converting units of time into units ofdistance.

The invention is composed of a radio trans- 10 mitting set, a mechanicalmeans of operating the transmitting set, a relay transmitter to pick upand re-broadcast the signals sent out from this mechanically operatedsending set, an antenna to pick up these relayed signals, a means ofamplification, a mechanical means of calculating the time required forthe signals to travel 1 to the relay station and return and convertingand registering this time in units of distance.

The relay stations used in the invention are permanently tuned and setso as to receive signals at one frequency and relay them at anotherfrequency, and when two or more relay stations are used as in marine oraerial navigation, each relay station has a slightly different tuning sothat by adjusting the tuning of the mechanically operated sending andreceiving set, any one of the relay stations may be contacted at will.

When the invention is used for aerial or marine navigation, the aircraftor ship to be navigated is equipped with the mechanically operatedsending and receiving set as herein described. When this mechanicallyoperated set is placed in motion and tuned to the frequency of the relaystation to be contacted, the set will transmit in rapid succession, anumber of radio signals or impulses, which will be picked up by therelay station and re-broa-dcast on a different frequency. The antenna ofthe mechanically operated radio receiving set willthen pick up thesereflected or relayed signals and transmit them to the radio receivingset where they are amplified and passed on to the super-sensitive timingdevice, where the time required for them to reach the relay station andreturn is mechanically calculated and converted from units of time tounits of distance. The units of distance are then registered on a visualinstrument.

It is possible to construct the invention so as to measure a widevariety of distances and to use units of mea'sure other than the mile.However, for simplicity I have considered an instrument of one thousandmiles capacity using the mile as a unit of measure.

Inasmuch as the radio circuits, motor (for driving the distributor), andthe governor or speed control mechanism used in the invention may be ofconventional design, I have not considered it necessary to include themin the drawings or specifications.

' One form of mechanism for operating the pri- 5 mary sending andreceiving set is shown in the accompanying drawings in which Fig. 1shows a section of the face of the rotor or balanced distributor disc A,the primary or. sending brush B,

the units" receiving brush 0, the tens receiving brush D, the hundreds"receiving brush E and the insulation F around these brushes.

The stationary commutator ring as represented by Figures 2, 3, and 4consists of three sections, one of which measures in units and whichwill 15 hereinafter be referred 'to as the units section, one of whichmeasures tens and units and will be referred to as the. tens section,and the last which measures hundreds, tens and units and will bereferred to as the hundreds section. 20

I Any number or combination of segments and-contact bars may be used inthis commutator.

Fig. 2 is a section of the stationary commutator showing. the face ofthe entire units section, of.

ten contact points or segments, G to G, the in- 5 sulation segments Hbetween the contact. points, the insulation rings I and I, the beginningof the tensfcontact section J, the endsof the tens and hundreds" sectionJ and K, and the primary out-put or sending contact point L.

Fig. 3 shows part of the tens section of the commutator ring. J and J.indicate two of the long contact bars which make up the tens section ofthe commutator and which are connected tothe tens section of the visualindicator. The 35 small segments G of the units. series are re peatedaround the entire circumference of the commutator, beginning anew everyten segments. Segments 1, 11, 21, 31, etc., are connected to the firstpoint or bulb of the visual indicator, while 40 segments 2, 12, 22, 32,etc., are connected to the second point or bulb of the indicator, etc.

Fig. 4 is a portion of the hundreds section of the commutator ring,showing a part of one of the contact bars K of the hundreds series, alsotwo 45 contact bars J, ofthe "tens series, and thirteen segments G ofthe "units" series. All contact points are separated by insulation.

Fig. 5 is a section of the continuous contact ring M which is stationaryand is placed on the- 50 opposite side of the rotor from the commutatorring. The point which contacts the brush Bis shown at N. This contactring M acts as a terminal base.

The commutator ring, of which Figures 2; 3 55 and 4 are sections, andthe continuous contact ring of which Fig. 5 is a section, are stationaryand are. mounted facing each other with the distributor disc of whichFig, 1 is a section, between. One end oi. the brushes C, D and E of thedistributor disc A is in continuous contact with the face of thecontinuouscontact ring M, while the opposite ends of the brushes C, Dand E contact segments of the varioussections oi the commutator as thedistributor brush revolves. Brush B is only in contact while it ispassing directly between contact points-N and L. In this way, brush 13serves the same purpose as the key of a conventional code telegraphinstrument.

Fig. 6 is a view showing the distributor disc A mounted on shaft P andlocated between the continuous contact-ring M and the commuator O alsovthe driving motor and speed control mechanism S, and operating switch T.Receiving brushesC, D, and E are shown in contact with ring M and thecommutator 0. The primary or sending brush B is also shown in contactbetween contact point N of the continuous contact ring and contact pointL of the commutator.

Fig. 7 shows the visual indicator Q. The 27 dots' on the face of thisinstrument indicate 2'7 small electric bulbs R. The plan of operationand method of reading this indicator are explained hereinafter.

Fig. 8 is a. diagrammatic view showing the invention as a whole. At theleft is shown the complete initiating station. At the right is therelaying or reflecting station. Thelong dashes between the antennae ofthe initiating transmitter and the receiver of the relaying stationindicate electro-magnetic impulses tuned to the frequency of the relaystation and transmitted by the initiating station; while the shortdashes between the transmitter of the relay set and the receiver of theinitiating station indicate returning radio impulses transmitted'on adiflerent irequency than those of the initiating transmitter.

If an electric impulse is broadcast thru point L at each revolution ofvdistributor disc A when brush B completes the electric circuit'betweenpoint N and point 1 disc A and brushes C, D and E will have passed somedistance around the commutator ring before the radio impulse reaches therelay station and returns. Inasmuch as distributor disc A is revolvingat a predetermined high rate of speed there will be a rapid successionof radio signals being broadcast thru contact points N, B and L and acorresponding rapid succession of returning signals thru brushes C, D orE to that point on the commutator with which the brushes C, D or E arein contact at the time the incoming signals are received. The time lapseupon which this point of contact depends constitutes a measurement ofthe distance between the mechanically operated sending and receiving setand the automatic relay set. By

tiating station with its mechanically operated sending and receivingset, commutator unit and visual indicator is located in the controltower of an airport, while the automatic reflector Q 6 station islocated in an aircraft which the control tower operator wishes tocontact.

The distributor disc A is set in motion by closing the switch T of thecontrol mechanism 8 and the initiating transmitter is tuned to thefrequency of the receiving 'set in the ship to be contacted. With eachrevolution of the distributor disc A the sending contact brush B isbrought directly between contact points N and L,

completing the primary or sending circuit. A"

series 01 short electro-magnetic impulses (one impulse for eachrevolution of disc A) is broadcast from the initiating transmitter. Thisseries of electro-magnetic impulses is picked up by the receivingantenna of the ship to which it is tuned and is re-transmitted on adiflerent frequency by the transmitter 01 the relay set. These relayedor retransmitted signals or impulses are again picked up by the receiverat the initiating station where they are amplified and passed to thecontinuous contact ring M, thru the brushes 0, D and E to the commutatoror selector 0. and thence to the signal board or visual indicator Q.

It is well known that the speed of radio waves is for all practicalpurposes the same as that of light, 1. e., 186,000 miles per second. Thesection of the commutator which is contacted by distributor brush 0 isdivided into one thousand segments and-the speed of the distributor discis 93 revolutions per second. Therefore, a radio wave will travel onethousand'miles' to a relay station and return while brush C, carried bydistributor disc A, makes one complete revolution. Inasmuch as brush 0contacts 1000 segments of the G or units" series of the commutator eachrevolution, and an electro-magnetic wave will travelv 1000 miles andreturn during the time required for disc A to complete one revolution,it is clearly understood that an electro-magnetic wave will travel onemile to a reflecting stationand return while brush 0 is passing any oneof the segmentsG. Each of the.1000 segments of the commutator series Gtherefore represents one mile of distance between the initiating andrelaying stations. 1

The final, or one thousandth segment position is a blank, or dummy, inthe units", tens and Y hundreds" series of the commutator, withinsulation material totake its place. Contact points N and L aresoarranged as to be cont'acted by B while brushes C, D andE are passingthe insulation which takes the placeot the one I thousandth segmentposition.

It would of course be impossible to have a bank of 1000 electric bulbs,each one to represent an individual segment of the commutator O. Forthat reason, the segments of the G series oi the commutator have beendivided into groups of ten, and a 27 bulb indicator serves amply tovisualize the calibration 01' this commutator selector.

The first segment contacted by brus'h C after brush B has left contactpoints L and N represents one mile of distance between the initiatingand reflecting stations, 1. e., at 9.3 revolutions per second, the timerequired for a given point on the rim of rotor A to travel oneone-thousandth part 01' a complete revolution, or the distance from onesegment to another, is the same as the time\ re.- quired for a radiowave to travel from an initiating station to a relay station one mileaway and return. This first, or number one segment of the'units series Gis wired to the first bulb of the upper or units" row of the visualindicator. Segments 2 to 9 of the, units" series G 'are wiredto bulbs 2to 9 respectively of the upper were present.

anemone or "units" 'row of the visual indicator. Thus, each bulb of theupper row on the indicating instrument represents one mile of distancebetween the initiating and reflecting station, or two miles of radiotravel. Hence, a light appearing in the fifth bulb would indicate 5miles of distance between the initiating and reflecting stations.

The tenth commutator segment position of the outer or units series is ablank, while a second series called the tens series J is contacted bybrush D at the time when brush C would contact the 10th segment G ifthat segment Brush D is in contactwith this first segment J of the tens.series during the portion of the revolution oi-disc-A which is requiredfor brush C to pass over segment positions 10 to 19 inclusive. the firstbulb of the middle or tens" row of nine bulbs on the visual indicator.

The second group of 9 individual segments G are wired respectively tothe 9 bulbs of the upper or units row as were the first 9 segments G.

Thus, if a radio impulse were returned from a relay station 15 milesfrom the initiating station it would reach the commutator disc whilebrush D was in contact with the first segment of the tens series J, andbrush C was in contact with the 15th segment of the units" series G, orsegment 5 of the second group of 10 individual segment positions. Thevisual indicator would one of the 100 groups of 10 segmentpositions willlght the first bulb in the upper or units row of the visual indicator,and likewise an electrical impulse passing from brush C to the second,third or fourth segments of any one of these groups would likewise lightthe corresponding bulb in the upper row of the visual indicator.

There are 99 segments in the tens series J, each individual segmentbeing equal to 10 segment positions of the units series, and each 10thsegment of the J series being blank, thus making 9 groups of segments inthe J series. The first segment of each of these groups is wired to thefirst bulb of the middle or tens row of the visual indicator, andlikewise the second, third'and fourth segments of each of these groupsare wired to the second, third and fourth bulbs of the middle row of thevisual indicator.

There are 9 segments in the hundreds series K,'each segment being equalto 100 segment positions of the units series. Segments'l to 9 of thehundreds" series are. wired to bulbs 1 to 9 respectively of the lower orhundreds row of the visual indicator. i

' The one thousandth segment position on the commutator is blank toallow the receiving instrument of the initiating station to be inactiveduring the sendingperiod of the transmitter, i. e.,

the period of the revolution of disc A when brush B isin contact withcontact points N and L. The

' time required for brush B to pass points N and L is brushes do notcontact two segments of the same series at the same time. Thus, sincethe length of the impulse transmitted by the initiating station is equalto one one-thousandth of a complete The firstsegmentJ is wired torevolution of the distributor diet. the returned,

or relayed impulse will require the exact time necessary for brush topass any one segment position of series (3., The insulation blocksbetween thesegments are just large enough that the leading edge of thebrushes C, D and E contact a new segment or segment position as soonasthe trailing edge has left the previous segment position. Thus, eachrelayed impulse will be received thru one segment only of any one seriesand no more than one bulb in each row of 9 bulbs on the visual indicatoris lighted at any one time. Neon bulbs are used on the visualinstrument. Ninety-three impulses per second are transmitted by brush 13thru points N and L--hence, 93 re turn impulses are received per secondthru brushes C, D and E to the indicating instrument. Therefore, if theoperator of the previously mentioned control tower were measuring thedistance to an aircraft 15 miles away, the 93 impulses per secondtransmitted thru brush B and points N and L,

would bereturned thru brushes 0 and D over segments one of the tensseries and fifteen of the units" series, to bulbs l of the middle rowand 50f the upper row, indicating 10 and miles respectively, or 15 milesas the distance between the mechanically operated sending and receivingset in the control tower and the automatic relaying or reflectingstation on the ship. Ninety-three impulses per second of the propervoltage are sufilcient to cause the neon bulbs to glow, and because ofthe'great rapidity, appear as a constant light to the human eye. Thesebulbs will continue lighted until the aircraft changes its positionsufiiciently to take itwithin the 14 or 16 mile zone at-which time bulbnumber 5 of the upper or' units row will cease to glow, and a light willappear in either 4 or 6 of the same row as the case may be. The firstbulb of the tens" row will remain lighted,

The antenna of the receiver at the initiating station is'of theso'-called directional type. This directional or range finding antennamakes it possible for the operator in the aforementioned control tower,or at any ship or land station equipped with the automatically operatedinitiating instrument herein described, to locate any ship, aircraft orany fixed or movable point which is equipped with a suitable relaystation.

It is the purpose of the inventor to provide. a safe and satisfactorymeans of navigation which is not subject to the disadvantages existingwith the means already in use.- Solar navigation is impossible in verystormy weather, and the time required for solar observations makes itunsatisfactory for aircraft navigation at any time. The

.radio beam is not as constant as it should be. and

at best gives little assistance in judging distance and none whatsoeverwhen fiying over uncharted territory.

The foregoing advantages conclusively establish thefact that theinvention herein described will serve a new and useful purpose.

Therefore, I claim:

An instrument substantially as herein described for mechanicallycalculating distance,

composed of a radio transmitting set, a mechanical means of operatingsaid. transmitting set wherein a brush mountedon a revolving disc ispassed between two contact points of the primary circuit of'saidtransmitting set in such a manner that the circuit is momentarily closedand an impulse is thereby transmitted'thru said transmittingset onceeachrevolution of said revolving disc, an automatic relay transmitter topick up and re-broadcast the signals sent out from this mechanicallyoperated sending set, an antenna to pick up these relayed signals, ameans of amplification such as any standard radio set, a mechanicalmeans of calculating the time required for the signalsto travel to therelay station and return wherein the returning or relayed radio signalsare transmitted from the standard receivmented commutator rings andthence to a bankaf three. tiers of electric bulbs (the suggested numberof bulbs being 27), forming a visual iniicator, said segmentedcommutator rings being iivided into series and wired to said bank ofelecv ;ric bulbs in such a way that a current passng thru segments 1,11, 21, 31 and so forth of he first bank of segments of said segmented:ommutator ring would be transmitted to bulb #1 in the first bank ofbulbsof said visual indi- :ator, and a current passed thru segments 2,12, i2, 32 and so forth would be transmitted to bulb #2 of the firstbank of electric bulbs of said vis- [8.1 indicator, and the remainingsegments of the irst bank in saidcommutator ring to be wired 1likemanner to the remaining bulbs of the first ank of bulbs in saidvisual indicator, thus dividag the first bank of segments on thesegmented ommutator ring into nine series of one hundred ctive segmentseach, with each series connected 2 a separate bulb in the first bank ofbulbs in aid visual indicator, while the tenth segment I each seriesremains a blank, and where the acond bank of segments of the segmentedcomiutator ring is divided into segments approxilately ten times thelength of the segments of 1e first commutator bank and arranged in suchmanner that while one of the said commutator isc brushes would besweeping any one of the roup of commutator segments one to-ten of therst commutator ring except the first group, the

second brush of the said commutator disc would be in constant contactwiththe face of the corresponding segment of the second series ofsegments of the segmented commutator ring, and the second series ofsegments of the segmented commutator ring are wired in the exact orderof the first series, that is, so that segments-#1, 11, 21, 31 and soforth, would transmit current to the first bulb of the second bank ofbulbs in the visual indicator and the remaining segments and bulbs wiredin like order, and also where the third bank of segments of thesegmented commutator ring is composed'of segments approximately tentimes as long as the segments in the second series of the segmentedcommutator ring, or approximately one hundred times as long as thesegments of the first series of-segments of.the segmented commutatorring, and the face of the segments of the third series of segments inthe segmented commutator ring are swept by the third brush in the saidrevolving commutator disc in such a manner that while' the said firstbrush of the revolving commutator disc is sweeping any group of onehundred segments of the first series of segments in the said segmentedcommutator ring except the first group of one hundred segments, and thesecond brush of said commutator disc is sweeping the ten segments of thecorresponding second series of segments in the segmented commutatorring, the third brush of said revolving commutator disc will be,sweeping the corresponding segment .of the third series of segments inthe segmented commutator ring, these segments being individually wired.-so that segment #1 is connected to bulb #1 of the third series of bulbson the said visual indicator, while segment #2 is connected to thesecond bulb of said visual indicator and the following segments of thethird series of segments of the said segmented commutator ring areconnected in like order to the remaining bulbs of the third bank ofbulbs in the said visual indicator.

- WARRINGTON C. WADEMAN.

